Klasky Csupo animated the short cartoons about the Simpson family which appeared on The Tracey Ullman Show (1987–1989) and continued this role on the half-hour adaptation of the characters, entitled The Simpsons, for its first three seasons (1989–1992).[3] Csupó was credited as "animation executive producer" and "supervising animation director".[4] Klasky Csupo animator and colorist Gyorgyi Peluce conceived the idea of the Simpsons characters having yellow skin, and Marge Simpson having blue hair, opting for something which "didn't look like anything that had come before."[5][6][7] Csupó liked the idea, although many of the show's producers at production company Gracie Films disapproved.[5][8] He noted "everybody kept saying, 'You can't have people with yellow skin', and I said, 'Why not?'"[8] Csupo successfully persuaded the producers and the show's creator Matt Groening to approve of the colors.[5] Groening liked the idea, feeling that attempts to re-create human skintone on cartoons always appeared "freakish".[7] Groening said of Csupó and Klasky, "What I love about them is their stuff looks like no one else."[8] The character design of The Simpsons character Dr. Nick Riviera is based somewhat on Csupó. The show's animators mistakenly believed the character's voice actor, Hank Azaria, was impersonating Csupó,[9] but Azaria said the voice was actually a "bad" imitation of Ricky Ricardo from I Love Lucy.[10]

His record label, Tone Casualties, founded in 1994,[1] released several industrial, noise, ambient and experimental music releases, including discs by Holger Czukay, Drew Neumann, Paul Schütze, Kuroi Mori, Borut Kržišnik, András Wahorn, Controlled Bleeding and his own works (sometimes under the pseudonym "Opus Crobag").

Csupó has six children (two of whom are from his business partner and ex-wife, Arlene Klasky),[12] Jarrett, Brandon, Ruby, Bowie, Romeo and Kelcy Csupo. Csupó is a big fan of Frank Zappa and credits Zappa with helping him learn the English language. His collection of Zappa albums were the only items he took with him when he fled his native Hungary in the 1970s.[1] When he worked on The Simpsons, he and Matt Groening, a fellow Zappa fanatic, tried unsuccessfully to persuade the series' producers to use Zappa's music on the show. Nonetheless, he was successful in securing the rights to Zappa's music for Duckman, and its first season contained songs from throughout Zappa's career including "Peaches en Regalia" and "Take Your Clothes Off When You Dance."